More sex may not always make you happier, according to new research published by the Society for Personality and Social Psychology. "Although more frequent sex is associated with greater happiness, this link was no longer significant at a frequency of more than once a week," lead researcher Amy Muise said. "Our findings suggest that it's important to maintain an intimate connection with your partner, but you don't need to have sex everyday as long as you're maintaining that connection."Some previous studies, and a plethora of articles and self-help books, have claimed that more sex equals more happiness. But this study, based on surveys of more than 30,000 Americans collected over four decades, is the first to find that association is not there after couples report having sex more than once a week on average. The study was not designed to identify the causal process, so does not tell us whether having sex up to once a week makes couples happier, or being in a happy relationship causes people to have more frequent sex (up to once a week).